Sofa



FIG. 1 is a perspective view of a sofa comprising the new design;

FIG. 2 is a top view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a rear view thereof; and,

FIG. 6 is a front view of an alternative embodiment of said new design having an indeterminable width.

The broken lines in the figures are for illustrative purposes only and form no part of the claimed invention. 

The ornamental design for a sofa, as shown and described. 